Refrigerating apparatus.



Patented Feb. 22,1910.

NVFNTO/i W. COOPER.

REFRIGERATING APPARATUS.

APPLICATION FILED DEC. 6, 1907.

W1 TNESSES:

To all whom may concern:

an STATES PATENT orric i;

WILLIAM coorna, or rrrrsnune, rnmvsnv.

- REFRIGERATING APPARATUS.

Be it known that I, WILIJAM Coornn, a

I citizen of the United States, and a resident of Pittsburg, in thecounty of Allegheny and State of Pennsylvania, have invented a new anduseful Improvement in Refrigerating Apparatus, of which the following isa specification.

My invention relates to the manufacture of ice and to artificialrefrigeration, and it has special reference to such refrigeratingapparatus as involves the absorption, and evaporation of gases andliquids.

The object of my invention is to providean' apparatus of the 'classabove indicated that shall be simple and inexpensive in construction andeffective, reliable and practicallyautomatic in operation.

-.-ip'paratus which has heretofore been utilized for the artificialproduction of ice and refri eration may be divided, in general, into twoclasses commonly known as compression. and absorption machines.compression machines of the prior art are entirely different inprinciple from the apparatus of my present invention and need not befurther-considered. The absorption machines of the prior art have, ingeneral, employed pumps or other mechanisms for providing a forcedcirculation of the fluids used as heat vehicles. According to my presentinvention, no such mechanisms are employed, the circulation beingproduced by the inherentcharacteristics of the liquids used and theaction of gravity upon them. 'As hereinafter set forth in detail, Iprovide a refrigerating apparatus in which two liquids, that boil atmaterially different temperatures. are used, the boiling point of onebeing sufiiciently low to produce the desired refrigeration within therange of working pressures. It is also essential that the liquid havingthe higher boiling point shall be ca pable of absorbing the vapor of theother liquid; in other words, the vapor or gas produced by the boilingof the liquid having the lower boiling pointmust be readily soluble inthe other liquid. The amount of gas or vapor which may be absorbed bythe liquid is dependent upon the temperature of the the less the asorption. Consequently, if

The.

Specification of Letters Patent. Patented Feb. 22, 191%,

Application filed December 6, 1907. Serial No. 405,385.

the liquid has absorbed a maximum amount of gas at a given temperatureand pressure, an increase in temperature Wlll expel a portion of the gasorvapor absorbed. The gas for the liquid having the lower boiling point,

although my invention is not restricted in this regard, and any suitablefluids having the necessary properties may be em loyed. Ammonia isspecially well adapted or this use,'since it is highly soluble in waterat ordinary temperatures and pressures and since it is easily liquefiedwithin the range of moderate working pressures and temperatures.

In general, my refrigerating apparatus of ammonia is contained and fromwhich ammonia gas is driven off by intermittent applications of externalheat, a subcondenser or dehydrator, a condenser in which the ammonia gasis condensed into anhydrous liquid ammonia, a storage reservoir whichreceives the liquid ammonia from the condenser and is completelyinsulated from external heat transfer, an evaporator which is suppliedwith liquid ammonia from the storage resercomprises a stlll or boiler inwhich a solution 7 voir and is completely filled with the liquid ammoniaat all times, and a tank or receptacle containing a bath of congealableliquid in which the evaporatoris immersed, said tank or receptacle beingdisposed in the space or chamber to be refrigerated. The condenser islocated at a higher level than that of the reservoir, and the evaporatoris located below the reservoir so thattthe liquid ammonia condensed maybe carriedto the reservoir and from thence supplied to the evaporator bythe action of gravity upon it without the use of expansion valves orother mechanism.

'The storage reservoir is of'suflicient size to receive all ofthe liquidammoniacondensed during the distillation process. The storage reservoirjust referred to is of great importance tomy invention, and greatlyimproved results may be obtained by' its use.

As indicated above, the evaporator is full 1 still s filled with anammonia solution ofevaporator 2 is higher than the liquid level ofliquid ammonia, even when the-boiler or one direction, by reason of thefact that I -maximum strength.

.that of Fig. 1, in which a modified arrangesupplied with energy fromany suitable in receptacle or still My invention is illustrated in theaccom- Special reference may now be had to Fig. panying'drawin s, inwhich 2, in whlch corresponding parts are desigigure 1 is a iagrammaticview of a sys natecl by the same reference characters. tern andapparatus arranged in accordance I here illustrated, the boiler orreceptacle 1 1s therewith, and Fig. 2 is a view similar to provided witha heater 1'5, which may be ment is disclosed. source, and a cooling coil16, which is located Referring to the drawings, with special within theboiler. vertical plpe section 7 reference to Fig. 1, the system hereillusis here surrounded by a acket 28 which t-rated' comprises areceptacle or boiler 1 forms a second condenser, through which thecommonly known as a still to which heat cooling fluid exhausted from thefirst'conmay be applied, a second receptacle 2, comdenser 4 may pass.The cooling device thus monly known as an evaporator, which comformed,which may be designated as a municates with the first, as hereinafterex-. dehydrator or subcondenser 17, is provided plamed, a storagereservoir 3', which comwith an exhaust pipe 18, which may eithermunicates with the receptacle 2, and a concommunicate directly witha'waste pipe 19 denser 4, which, as shown, is interposed beor with thecooling C01l 16 of the boiler 1.

tween the receptacle or boiler 1 and the. according to the positionoccupied by a storagetank 3, communication being estabthree-way cock 20.The boiler or receptacle lished between these two members by a pipe 1 isprovided with a pressure gage 21 and 5. The storage reservoir 3 does notnecesa pressure-relieving device 22, which is desarily communicatedirectly with the conscribed and claimed in my co-pending applidenser,but it must communicate with the cation, Serial N 0. 405,386, filed ofeven date evaporator, since it is intended to keep the herewith..Communication is established evaporator full of anhydrous liquidrefrigerfrom .the lower extremity of the evaporator ant at all times. Acheck valve is located 2 to the pipe 5 by a pipe 23, which is joined inthe pipe 5, near the receptacle 1, so that to the latter at anyconvenient point, befluid may escape from the receptacle into tween thestorage tank 3 and the condenser the .pipe but may not return by thesame 4. Stop cocks 24 and 25 are provided at passage-way. 'As the pipe 5extends through the outer extremities of both. the receptacle thecondenser it is slightly inclined, so that 2 and the storage reservoir3, the pipe 23 it drains into the storage reservoir 3 and of this figurebeing substituted for the pipe the evaporator 2. From some point in the13 of Fig. 1. The storage reservoir 3 is pipe 5, between the boiler andthe condenser, insulated against external heat absorption, a re rn g-p p8 s p vided, by a coating or jacket 26; and the receptacle whlch isconnected to the bottom of the re 2 is immersed in a bath of brine orother cepftacle or'bo11er1. A check valve 9 may suitable congealableliquid contained in a preferably be located in this return pipe, in tankor receptacle 27. The freezing point order to prevent fluid from passingoutrof of this liquid corresponds approximately to the boller orreceptacle 1 1n th1s d1rect1on, the desired temperature ofrefrigeration, so although this valve is not essential to the that, byfreezing and thawing the liquid,

operation of the system. as hereinafter explained, the temperature I Thecondenser 4 comprises a jacket 10 of the chamberor refrigerating space29 which surrounds a materlallength ofthe 1nmay be maintained at asubstantially concllned sectlon of the pipe 5 and which is stant value.

supplied with water or other cooling fluid The operation of the systemis as follows:

from any convenient source, through a pipe Assuming that cooling wateris flowing 11, an escape or. outlet port being provided through thecondenser 4 and thesubcon through a pipe 12. lnce the condenser denseror dehydrator 17; that the boiler or forms no part of my presentinvention, anv still 1 is filled with a strong, solution of sultabletype, many of which are well ammonia at a low temperature; that theknown, may be employed 1n lieu of that evaporator 3'is full of liquidammonia, and

illustrated in the drawlngs. that the insulated reservoir 3 ispractically The/lower extremity of the evaporator 2, empty; if heat isnow applied to the boiler 1n the arrangement of Fig. 1, should prefer-1, ammonia gas will be driven off from the ably be somewhat above theliquid level in solution into the condenser 4. It will here thereceptacle or still 1, and communication .be condensed into liquidammonia and will -may be established from' one to the other flow intothe storage reservoir 3 toward t rough a pipe 13, under certainconditions which the condenser is inclined. When heat hereinafterexplained, the pipe being noris first applied to the generator 1, it isnecmally closedby a valve 14.: Circulation in essary for the storagereservoir 3 to be prao the plpe 18 can never take place, except intically empty, but it is also necessary for 3 generator is 'theevaporator 2' a) b full of liquid amfreezes substantially at the desiredtemperature of refrigeration,in order that a certain amount of'therefrigeration etfected during the evaporation period may be utlllzed infreezing the brine, the melting of the ice so formed being utilized formaintaining the constant refrigerating temperature during the time whenheat is applied to the generator 1. As the application of heat to thecontinued, the storage reservoir 3 is gradually filled with the liquidammonia. this process being stopped onlyv when the solution in thegenerator is weakened to a point after which there is no advantage inapplying more heat. As soon -transferred to the evaporator.

as the heat is shut ofi, the temperature of the liquid in the, generator1 will, of course, decrease, apd, in order to aid the cooling of thegenerator. water may be passed through a cooling toil 16 within it. Asthegenerator 1 is cooled, the gas over the surface of the solution willbe absorbed and the pressure within the apparatus reduced. As no gas canenter the top of the generator 1 owin to the check valve/6 in the outletpipe I which connects the top of thege1ierator 1 and the condenser lathepressure in the gen-- erator will be lowered until the gas is forced inat the bottom through a second pipe 8' between the adjacent end of thecondenser 4 and the bottom of the generator 1. having a checkvalve 9,from which it will bubble up through the weak solution and will bepromptly up through the liquid will also insurethe prom ?i absorption ofa'hy 'slightfamount of gas w 'ch may leak through the check valve (3 inlation efiected. As this action continues, the pressure in the reservoir3 and in the evaporator 2 is gradually reduced until itreachesthe'pressure corresponding to the tempera-.

ture of the refrigerator. Up to this point there is no gas produced inthe'evaporator, for the reason that the temperature there is low. Thestorage reservoir 3, which was at the temperature of the condenser whenthe absorption began, is now lowered in temperature as well as theliquid ammonia it contains. until both are at the temperature of theevaporator '2, after which no action takes place, and no ammonia gas isformed 1n the reservoir, the action belng There will'be no'ammoma gasformed in the reservoir 3, for the reason that it is absorbed. Thepassing of theigas theoutlet pipe Thy reason of the circu-' insulatedagainst the absorption of external heat by the jacket 26, so that it isimpossible, according to well known principles, for the liquid ammoniacontained in it to boil. By this means, the action is practicallyoonfined to the evaporator after the liquid in the reservoir is at thetemperature of the liquid in the evaporator. The liquid ammonia in theevaporator 2 continues to boil and take up heat from the refrigeratoruntil the solution in the generator 1 15 again saturated, to a maximumde ree at the pressure of the evaporator an at the temperature of thewater in the cooling coil 16 with which the generator is provided. Afterthis point is reached, the cycle is again repeated by applying heat tothe generator 1.

During the absorption of the ammonia gas .by the solution in thegenerator, the action is very much more rapid at first when thesolution'is weak than atthe end of this process when the solution issaturated. This condition'would tend to make the temperature of therefrigerator vary, if the heat were taken up directly from therefrigerator by the liquid ammonia. However, this variation is avoidedby surrounding the evaporator with brine of the roper strength for thetemperature require and freezing a portion of it while the absorption ismore rapid, thus producing a supply of refrigeration in the form of iceto be drawn upon the time that the absorption is less rapid andduringthe period of distillation.

The fimction of the subcondenser or dehydratonli" is to separate anywater vapor, which may be carried out of the generator during thedistilling process, from the ammonia gas before it reaches thecondenser, the water returning through the lower connection used by thegas during. the evaporationprocess. The How of water through the coolmgcoil 16 must be so regulated'that the solution will be cooled only at arate corresponding to the absorption of ammonia gas. In cool weather orunder some conditions. it may be desirableto reduce the amount ofrefrigeration supplied. Vhile this is automatically taken care of by thefreezing of the brine, it canbe still further controlled by the amountof ammonia distilled outateach cycle or by making the cycles cover alonger period of time. In other words, if a little refrigeration isdesired, a little heat should be supplied, the apparatus being found towork as well at one rate as it does at another and being alwaysautomatic.

1 The apparatus described is practically a'u tomatic and continuous, theonly attention required being to start and stop the heater for theboiler at times which are predetermined and which when once determinedare constantfor any given device. A substan-.

tially constant, uniform temperature is maintained in the refrigeratorby reason of freezing theliquid contained in reservoir 27 I thecongealable liquid, and a heat-insulated during the evaporation period,the ice formlng a reservoir of stored cold, which maintains thetemperature during the distilling period.

.Itflis conceivable that various modifications in the size andproportions of the apparatus illustrated may be effected within thescope of my invention, and I desire. that only such limitations beimposed as are-indicated in the appended claims.

I claim as my invention:

1. Refrigerating apparatus comprising a still or boiler,-an evaporator,a' condenser,

and a storage reservoir interposed between the condenser and theevaporator and above the evaporator-for supplying refrigerating liquidthereto directly by gravity, said reservoir having a coating or jacketof heat-insulating material for confining the evaporating process to theevaporator.

2. Refrigerating apparatus comprising a still or boiler having an outletat the top and an inlet at the bottom, an evaporator or expansiondevice, a storage reservoir communicating therewith and arranged todrain thereinto by gravity, a condenser connected to the top of thestill or boiler and draining into the storage reservoir, a shunt pipeconnection between the condenser inlet and the bottom of the still orboiler, and means for preventing an inward flow at the top of the stillor boiler.

3. Refrigerating apparatus comprising a still or boiler, an evaporatoror expansion .device, a storage reservoir above the-evaporator andarranged to drain thereinto' by gravity and provided with a jacket ofheat insulating material, a condenser between the reservoir and thestill or boiler and arranged to drain into the reservoir, pipes joiningthe condenser to both the bottom and the top of the still or boiler, andmeans for preventing an inward fiow at the .top of the still or boiler.

4. In a refrigerating apparatus, the combination with a chamber to becooled, a receptacle containing congealable liquid, disan evaporatorimmersed in.

posed therein,

a lower level than the evaporator pipes connecting both the top andbottom of the still with the receiving end of the condenser, and meansfor preventing an outward flow at the bofltom and an inward flow at thetop of the sti. p

5. Refrigerating apparatus comprising a stilltor boiler, an evaporatororexpansion device, a storage reservoir provided with a heat insulatingcovering and communicating directly with the evaporator or expansiondevice and draining thereinto by gravitv, and a condenser connected tothe outlet 0 the still or boiler and arranged to drain into the storagereservoir. 1 s

6. Refrigerating apparatus comprising a still or boiler, an evaporatoror expansion device, a storage reservoir provided with a heat insulatingcovering and communicating with the evaporator or expansion device andarranged to drain thereinto b gravity, a condenser connected to theoutle still or boiler and arranged to drain into the storage reservoir,a valve controlled drain pipe connected to the bottom of the evaporatoror expansion device, and a valve at the inlet end of thestoragereservoir.

7. Refrigerating apparatus comprising a still or boiler, an evaporatoror expansion "device, a storage reservoir above said evaporator orexpansion device and arranged to drain thereinto by gravity, a condenserconnected to the boiler or still and arranged to drain by gravity intothe storage reservoir, and piping arranged to conduct the vapor from theevaporator or expansiondevice through the condenser and to-the bottom ofthe still or boiler.

In testimony whereof, I have hereunto subscribed myna-me this; 4th dayof Dec,

WILLIAM COOPER." Witnesses: 5

, R. J. DEARBORN,

1 BfRNEY HINES.

